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| United States Patent |
5,649,828
|
|
Kawashima
|
July 22, 1997
|
Writing board system
Abstract
A writing board system comprises a white board having a writing surface for
receiving a written mark thereupon, a liquid tank filled with water liquid
for erasing the written mark from the writing surface, an applicator for
applying the liquid in the liquid tank onto the writing surface, and a
writing implement having an ink including at least one electron donative
coloring compound selected from the group consisting of
2-{2-[4-(dodecyloxy)-3-metoxyphenl]-ethenyl}quinoline,
3-cyclohexylamino-6-chlorofluoran, 3-diethyl amino benzo [a]-fluoran,
3-(4-diethylamino-2-etoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphtha
lide, 3.3 bis(4-diethylamino-2-etoxyphenyle)-4- azaphthalide, and
3-cyclohexyl methyl amino-6-methyl-7-anilinofluoran, and an electron
acceptive developing compound selected from the group consisting of zinc
salicylate and bisphenol A.
| Inventors:
|
Kawashima; Kiyoharu (5-7, Esaka-cho 5-chome, Suita, Osaka-fu, JP)
|
| Appl. No.:
|
489368 |
| Filed:
|
June 12, 1995 |
Foreign Application Priority Data
| Jun 29, 1994[JP] | 6-171915 |
| Dec 20, 1994[JP] | 6-335638 |
| Current U.S. Class: |
434/411; 434/408; 434/417 |
| Intern'l Class: |
B43L 001/00 |
| Field of Search: |
434/408,417,412,411
106/19 A,21 A,22 B
|
References Cited
U.S. Patent Documents
| 1227205 | May., 1917 | Sartakoff | 434/411.
|
| 3163943 | Jan., 1965 | Bell.
| |
| 4907903 | Mar., 1990 | Kawashima | 401/151.
|
| Foreign Patent Documents |
| 679884 | Apr., 1966 | BE.
| |
| 700613 | Jun., 1967 | BE.
| |
| 1059272 | Jul., 1979 | CA.
| |
| 1518669 | Feb., 1968 | FR.
| |
| 2712492 | Sep., 1978 | DE.
| |
Other References
Patent Abstracts of Japan, vol. 018, No. 619 (C-1278) 25 Nov. 1994.
Patent Abstracts of Japan, vol. 940, No. 012 6 Dec. 1994.
|
Primary Examiner: Smith; Jeffrey A.
Attorney, Agent or Firm: Birch, Stewart, Kolasch & Birch, LLP
Claims
What is claimed is:
1. A writing board system comprising a white board having a writing surface
for receiving a written mark thereupon, a liquid tank filled with a water
for erasing the written mark from the writing surface, an applicator for
applying the water in the liquid tank onto the writing surface to erase
the written ink, and a writing implement having an ink for forming the
written on writing surface including
at least one electron donative coloring compound selected from the group
consisting of
2-{2-[4-(dodecyloxy)-3-metoxyphenl]-ethenyl}quinoline,
3-cyclohexylamino-6-chlorofluoran,
3-diethyl amino benzo[a]-fluoran,
3-(4-diethylamino-2-etoxyphenyl)-3-(1-ethyl-2-
methylindol-3-yl)-4-azaphthalide,
3.3-bis(4-diethylamino-2-etoxyphenyle)-4-azaphthalide, and
3-cyclohexyl methyl amino-6-methyl-7-anilinofluoran, and
an electron acceptive developing compound selected from the group
consisting of zinc salicylate and bisphenol A.
2. The writing board system of claim 1, wherein the applicator comprises a
rubbing element for absorbing the water and rubbing on the writing surface
together with the water therein.
3. The writing board system of claim 2, wherein the rubbing element is a
sponge.
4. The writing board system of claim 2. wherein the rubbing element is a
brush.
5. The writing board system of claim 1, wherein the liquid tank is
connected to a pump for feeding the water in the liquid tank onto the
writing surface.
6. The writing board system of claim 1, wherein the applicator has a blade
rubber for dripping the water on the writing surface.
7. The writing board system of claim 1, wherein the white board is a board
having a writing surface at least on one side, and the applicator is
fitted to a sliding frame extending above the writing surface and being
supported movably along the writing surface.
8. The writing board system of claim 1, wherein the white board comprises a
loop sheet having the writing surface on an outer circumference and a
support frame rotatably supporting the loop sheet, and the applicator is
fitted to the support frame.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a writing board device for erasing the
written mark on a white board by applying water or other liquid on the
writing surface.
FIELD OF THE INVENTION
Recently, in classroom, conference, meeting, briefing or the like, instead
of the blackboard using chalk, the whiteboard for writing with water-based
felt pen or the like is widely used. In this kind, enamel or paint is
baked at high temperature on the surface of a board of steel or the like
to form a non-osmotic smooth writing surface, and the writing implement is
a felt-tipped pen having powder pigment suspended and agitated in alcohol.
Therefore, the written mark is only a deposit of powder pigment without
binder, and it can be easily erased by wiping with an eraser using a dry
cloth or the like.
In such conventional writing implement, however, the wiped powder pigment
is transferred to the eraser, and it is frequently required to clean the
eraser itself, or the pigment scatters about to contaminate the
environment.
Accordingly, the present inventor disclosed, in the Japanese patent
application (application No. Hei. 6-218089), a novel anhydrous ink mixing
an electron donative coloring compound of one or more types selected from
a group consisting of
2-{2-[4-(dodecyloxy)-3-metoxyphenl]-ethenyl}quinoline,
3-cyclohexylamino-6-chlorofluoran,
3-diethyl amino benzo[a]-fluoran,
3-(4-diethylamino-2-etoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthal
ide,
3.3-bis(4-diethylamino-2-etoxyphenyle)-4-azaphthalide, and
3-cyclohexyl methyl amino-6-methyl-7-anilinofluoran, and an electron
acceptive developing compound selected from a group consisting of zinc
salicylate and bisphenol A, and proposed to solve the above problems by
using it.
The ink develops a color by molecular contact between the coloring compound
and developing compound, and returns colorless by losing the effect of
developing compound by contact with water, and by making use of this
character, the written mark can be erased by decoloring the ink itself by
chemical reaction by water, not by wiping off the pigment itself.
Therefore, for erasing the written mark of this ink, new erasing means
different from the conventional eraser such as dry cloth is needed.
SUMMARY OF THE INVENTION
The invention is hence devised in the light of such situation, and it is an
object thereof to present a writing board device capable of solving the
problems by applying water in the liquid tank on the writing surface.
According to one aspect of the present invention, a writing board device
comprising a white board having a writing surface to be written upon by a
writing implement, a liquid tank filled with liquid for erasing the
written mark, and an applicator for applying the liquid in the liquid tank
onto the writing surface.
The writing implement preferably has an anhydrous ink comprising an
electron donative coloring compound of one or more types selected from the
group consisting of
2-{2-[4-(dodecyloxy)-3-metoxyphenl]-ethenyl}quinoline,
3-cyclohexylamino-6-chlorofluoran,
3-diethyl amino benzo[a]-fluoran,
3-(4-diethylamino-2-etoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthal
ide,
3.3-bis(4-diethylamino-2-etoxyphenyle)-4-azaphthalide, and
3-cyclohexyl methyl amino-6-methyl-7-anilinofluoran, and an electron
acceptive developing compound selected from the group consisting of zinc
salicylate and bisphenol A, and the liquid is water.
The applicator comprises preferably a rubbing element composed of sponge or
brush which soaks up the liquid and rubs on the writing surface together
with the liquid.
The device also comprises preferably a pump for feeding the liquid in the
liquid tank onto the writing surface, and/or a blade rubber for dripping
the liquid applied on the writing surface.
The writing board device of the invention applies liquid, for example,
water onto the writing surface by using an applicator. Therefore, the
written mark by the ink proposed in the Japanese patent application
(application No. Hei. 6-218089) can be erased easily and uniformly, and
new writing is allowed after being dried, and soiling of the surroundings
can be prevented.
As the applicator, when a rubbing element rubbing the writing surface is
used, if the writing surface is processed by mat treatment, the ink and
water getting into tiny asperities on the mat treated surface are easily
brought into mutual contact to decolor with assurity. Moreover, the
decolored ink itself is scraped off the writing surface by rubbing, and
therefore if, for example, the coloring compound for the ink composed of
zinc salicylate and bisphenol A is applied on the writing surface, the
writing surface can be kept clean without coloring again. Besides, the
device comprises a liquid tank, and is capable of maintaining the
decoloring and cleaning capacity for a long time. Still more, by removal
of the ink, water is not degenerated or contaminated, and it is safe, and
the water can be recycled, for example, by filtering with a filter, and
the maintenance is enhanced.
When the rubbing element is used, for example, when a pen for a
conventional whiteboard is used as the writing implement, it can be
removed cleanly by water and rubbing, without scattering the powder
pigment, and the scope of use can be expanded.
In addition, if the white board is formed by a board, and the applicator is
mounted on a sliding frame extending above the writing surface and being
movable along the writing surface, nearly the entire surface of the
writing surface can be effectively by moving the sliding frame from one
end to the other end of the writing surface. Similarly, if the white board
is formed by a loop sheet and a support frame rotatably supporting the
loop sheet, and the applicator is disposed on this support frame, the
nearly entire surface of the writing surface can be cleaned by rotation of
the loop sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will now be described, by way of
example, referring to the attached diagrammatic drawings, in which:
FIG. 1 is a perspective view showing a device of a first embodiment of the
invention,
FIG. 2 is its schematic sectional view,
FIG. 3 is a perspective exploded view showing a sliding frame and an
applicator,
FIG. 4 is a sectional view showing application,
FIG. 5 is a sectional view showing operation in moving state of the
applicator,
FIG. 6 is a sectional view showing other embodiment of a rubbing element,
FIG. 7 is a sectional view showing a different embodiment of a rubbing
element,
FIG. 8 is a perspective view showing a device of a second embodiment of the
invention,
FIG. 9 is its schematic sectional view,
FIG. 10 is a schematic sectional view showing other another embodiment of a
rubbing element,
FIG. 11 is a schematic sectional view showing a different embodiment of a
rubbing element,
FIG. 12 is a schematic diagram showing other another winding state of a
sheet,
FIG. 13 is a partial perspective view showing a different embodiment of a
white board,
FIG. 14 is a front view showing a device of a third embodiment of the
invention,
FIG. 15 is its perspective view,
FIG. 16 is its schematic sectional view,
FIG. 17 is a schematic sectional view showing a drive shaft,
FIG. 18 is a partial perspective view for explaining a liquid tank,
FIG. 19 is a perspective view showing a coupler,
FIG. 20 is a schematic sectional view showing other embodiment of a rubbing
element, and
FIG. 21 is a schematic perspective view showing a different embodiment of
the sheet winding method.
DETAILED DESCRIPTION OF THE INVENTION
A writing board device 1 comprises a white board 2 having a writing surface
S to be written upon by a writing implement, a liquid tank 5 filled with
liquid for erasing the written marks, and an applicator 7 for applying the
liquid in the liquid tank 5 onto the writing surface S.
The writing implement is preferably a felt-tipped pen or the like using an
ink mixing an electron donative coloring compound of one or more types
selected from the group consisting of
2-{2-[4-(dodecyloxy)-3-metoxyphenl]-ethenyl}quinoline,
3-cyclohexylamino-6-chlorofluoran,
3-diethyl amino benzo[a]-fluoran,
3-(4-diethylamino-2-etoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthal
ide,
3.3-bis(4-diethylamino-2-etoxyphenyle)-4-azaphthalide, and
3-cyclohexyl methyl amino-6-methyl-7-anilinofluoran, and an electron
acceptive developing compound selected from the group consisting of zinc
salicylate and bisphenol A, in an anhydrous solvent such as ethanol and
alcohol. As the liquid for erasing the written mark, for example, water is
used.
The chemical formula of the electron donative coloring compound is shown
below, and examples of ink using the electron donative coloring compound
are listed in Table 1.
__________________________________________________________________________
*2-{2-[4-(dodecyloxy)-3-metoxyphenl]-ethenyl} quinoline
##STR1##
*3-cyclohexylamino-6-chlorofluoran
##STR2##
*3-diethyl amino benzo[a]-fluoran
##STR3##
*3-(4-diethylamino-2-etoxyphenyl)-3-(1-ethyl-2-
methylindol-3-yl)-4-azaphthalide
##STR4##
*3.3-bis(4-diethylamino-2-etoxyphenyle)-4-azaphthalide
##STR5##
*3-cyclohexyl methyl amino-6-methyl-7-anilinofluoran
##STR6##
TABLE 1
__________________________________________________________________________
Sample
No. 1
No. 2 No. 3
No. 4
No. 5
No. 6
No. 7
Color of Ink (wt %)
yellow
orange yellow
pink
sky blue
green
purple
black
__________________________________________________________________________
*2-(2-[4-(dodecyloxy)-3-metoxyphenl]
5 5
ethenyl) quinoline
*3-cyclohexylamino-6-chlorofluoran
7
*3-diethyl amino benzo[a]-fluoran
12 6
*3-(A-diethylanino-2-etoxyphenyl)-3-(1-ethyl
0.3
2-methylindol-3-yl)-4-azaphthalide
*3.3-bis(4-diethylamino-2-etoxyphenyle)
3 0.25
4-azaphthalide
*3-cyclohexyl methyl amino-6-methyl 15
7-anilinofluoran
*alchohols solvent 69 66.2 55.5
73 68.5
68 52.5
*zinc salicylate 5 5.8 9 3 5.25
4.7 9
*nonionic surface active agent
21 21 20.5
21 21 21 20.5
__________________________________________________________________________
In the device 1A of a first device shown in FIG. 1 to FIG. 7, the white
board 2 is a board 9, and the applicator 7 is provided on a sliding frame
3 movable along the writing surface S.
The board 9 is a wide rectangular white board, and on at least one side
thereof is formed a substantially white writing surface S by baking enamel
or paint at high temperature on a steel surface. The writing surface S may
be processed by mat treatment or the like to decrease the gloss so that
reflection of the illuminating light is suppressed. The board 9 is fixed
and supported on a support frame 15 13 in this embodiment.
The support frame 13 is a portal framework mutually joining an upper
lateral frame and vertical frames 16, 16 for supporting the upper edge and
both side edge of the board 9. Between the vertical frames 16, 16, a lower
lateral frame 17 is stretched, extending nearly parallel across an
interval 18 from the lower edge of or the board 9. A leg 19 having a wheel
(not shown) of caster or the like is disposed at the lower end of each
vertical frame 16. In the embodiment, in the upper and lower lateral
frames 15, 17, guide rails 20 extending horizontally along each lateral
frame and opening at the rear end are individually formed. The sliding
frame 3 is supported by the guide rails 20 so as to be free to move
laterally along the writing surface S.
The sliding frame 3 comprises upper and lower support arm pieces 22, 23,
which have rollers 21 rolling on the guide rail 20 and extend forward
across above the lateral frame 15 and below the lateral frame 17, and a
shell 25, which extends vertically above the writing surface S by linking
between the support arm pieces 22, 23. In this embodiment, the sliding
frame 3 moves laterally along the guide rail 20 by manual pushing and
pulling operation in the lateral direction. On the shell 25 of the sliding
frame 3, a pair of applicators 7, 7 are provided parallel through a grip
27 having a handle 25 for manual operation. The shell 25 is, as shown in
FIG. 3, formed in a pi-section folding side pieces 25B, 25B extending
backward at both side edges of a base piece 25A parallel to the writing
surface S, and mounting pieces 30, 30 for mounting the grip 27 project
backward above and beneath across a gap nearly in the middle of the base
piece 25A.
The grip 27 is, as shown in FIG. 3 and FIG. 4, formed in a T-section
comprising a pivotal part 27A having a pivotal point J1 mounted on the
mounting pieces 30 around the vertical axial center, and pivotal support
parts 27A, 27C having pivotal support points J2, J3 for surrounding the
pair of applicators 27B, 27C around the vertical axial center. The pivotal
point J1 is positioned on the perpendicular bisector of the pivotal
support points J2, J3, and the pivotal part 27A has the handle 27
projecting forward on the perpendicular bisector. A wide insertion port 31
for passing the handle 26 is pierced in the shell 25 of the sliding frame
3.
Therefore, as shown in FIG. 5, by the moving operation in, for example, the
right direction by the handle 26, the grip 27 tilts about the pivotal
point J1 from the reference state Y1 perpendicular to the moving direction
F of the handle 26 to the slant state J2 of the handle 26 tilting in the
moving direction until, for example, abutting against the side end of the
insertion port 31. The sliding frame 3 moves laterally in the same
direction F in this slant state Y2, and at this time one pivotal support
point J2 retreats by distance L1 to the spacing side from the writing
surface S by this tilting, while the other pivotal support point J3 moves
forward by the distance L2 to the approaching side. Therefore, the grip 27
functions as changeover means of the applicators 7 by tilting the handle
26 in the moving direction F when moving the sliding frame 3 laterally, or
pressing and rubbing selectively only the applicator 7 of the moving
direction F side, out of the parallel applicators 7, 7, on the writing
surface S.
Each applicator 7 comprises, as shown in FIG. 3 and FIG. 4, a long holder
having a recess 32 opening backward and extending vertically nearly along
the overall height of the writing surface, and a feed pipe 34 and a
rubbing element 37 are provided in the recess 32 of the holder 33. The
holder 33, in this example, is formed nearly in a pi-section folding side
plate pieces 33B, 33B at both side edges of the base plate piece 33A, and
a pivotal pieces 33C mounted on the grip 37 projects forward at the
position of the pivotal support points J2, J3 in the base plate piece 33A.
Between the grip 27 and holder 33, it is preferable to dispose position
maintaining means (not shown) using a spring material or the like, in
order to keep the rubbing surface 37S of the rubbing element 37 opposite
to the writing surface S in the reference state Y1. At this time, in the
slant state Y2, as shown in FIG. 5, the retreating side holder 33 has its
side plate piece 33B overlapping the side piece 35B, while the forwarding
side holder 33 has the rubbing element 33 pressed against the writing
surface S, thereby keeping the opposite position by overcoming the
position maintaining means.
The feed pipe 34 comprises an upstream side pipe 34A having the lower end
communicating with the liquid tank 5 and extending upward, and a
downstream side pipe 34B folded back from the upper end of the upstream
side pipe 34A through a U-part and closed at the lower end extending
downward, and is disposed nearly along the center of the recess 32. In the
downstream side pipe 34B, plural pores 36 opening toward the writing
surface S are pierced at proper pitches. These pores 36 form nozzle holes
for discharging the liquid supplied from the liquid tank 5 toward. the
writing surface S.
The liquid tank 5 is a container installed in the lower part of the sliding
frame 3, and a cartridge type water tank 43 is detachably installed in
this example to hold always a specified amount of liquid, and the liquid
is supplied. Between the liquid tank 5 and the feed pipe 34, a feed flow
path 12A is connected, in which a pump 6 for pumping the liquid in the
liquid tank 5 and a changeover valve 35 such as three-way valve for
selectively communicating with the feed pipe 35 of the applicator 7 of the
forwarding side of the pumped liquid are interposed. The pump 6 and
changeover valve 35 are provided at the rear side of the shell 25 of the
sliding frame 3. A switch 11 for operating the pump 6 and changeover valve
35 comprises on/off switches 11A, 11B provided at both side edges of the
insertion port 31 of the sliding frame 3, and the pump 6 is actuated as
the handle 26 approaches the tilting side switch in the lateral move. The
changeover switch 35 is also actuated by this tilting side switch, thereby
opening the flow path to the applicator of the tilting side, that is, the
forwarding side applicator, and closing the flow path to the retreating
side applicator.
The rubbing element 37 is formed of, in this example, an elastic sponge
material of high water absorption property. For example, in a block form
in a rectangular section, it is disposed at both sides of the feed pipe
34. As the sponge material, the cellulose sponge mainly composed of wood
pulp and non-wood pulp such as husk and grass roots is preferable because
it is high in density of continuous foams and excellent in water
absorption. The rubbing element 37 has such a size that the rubbing
surface 37S confronting the writing surface S may be spaced from the
writing surface S in the reference state Y1, and presses tightly with an
compression allowance L3 at the forward position in the slant state Y2.
Therefore, the applicator 7 can close the space G between the rubbing
elements 37, 37 connecting the feed pipe 34 in the pressed state, thereby
assuring the liquid discharged from the nozzle holes 36 to be applied
sufficiently on the writing surface S without scattering outside. The
rubbing element 37 partly absorbs water, and rubs against the writing
surface S with the discharged liquid and absorbed liquid to apply the
liquid on the entire width of the writing surface S, and rubs the writing
surface S. Rubbing means herein to rub against each other with a specific
pressure.
By forming the rubbing element 37 by a sponge material of high water
absorption property, it can rub together with the liquid, having an
adequate pressure, without injuring the writing surface S, and the ink
securely contacts with the liquid to decolor, and the decolored ink can be
removed from the writing surface S. To enhance the rubbing effect, the
rubbing element 37 is preferably formed in a rectangular block with an
increased rubbing surface. Or to increase soaking of liquid of the rubbing
element 37, tiny holes toward the rubbing element 37 may be formed in the
downstream side pipe 34B.
The applicator 7 in this embodiment is a rubber blade 39 for accelerating
drying by dripping the liquid applied on the writing surface S. The rubber
blade 39 is made of an elastic material, and is disposed, in each
applicator 7 as shown in FIG. 4, at the further inside of the rubbing
element 37A of the inward side, or, in this example, between the rubbing
element 37A and the adjacent side plate piece 33B. The rubber blade 39 has
a height nearly same as the rubbing surface 37S, and is tapered in
section, thereby forming a gap D against the adjacent rubbing element 37A.
Therefore, the rubber blade 39 presses to the writing surface S after
application when the sliding frame 3 moves laterally, and drips the liquid
applied on the writing surface S, thereby allowing new writing on the
writing surface S. The dripped liquid passes through the gap D, and flows
down effectively. Further inside of the rubber blade 39, a dry wiper 45
made of cloth material or sponge material of high water absorption
property such as felt can be disposed exchangeably, so that the writing
surface S can be dried more securely.
Beneath the applicator 7, excessively supplied liquid from the nozzle holes
36 and the liquid dripped by the rubber blade 39 are recovered in a pan 40
to prevent soiling of the floor. This pan 40 is, in this embodiment,
attached to the shell 25 of the sliding frame 3, and is extended to the
rear side of the writing surface S through the gap 18. The pan 40 and the
liquid tank 5 communicate with each other through a feedback path 12B, and
a filtering device 42 having an exchangeable filter to be reusable by
filtering the recovered liquid is disposed in the feedback path 12B. In
this embodiment, therefore, a liquid circulation route is formed by the
feed flow path 12A and feedback path 12B, and the liquid consumption is
decreased, while soiling of the device by the liquid is prevented.
Besides, the liquid in the liquid tank 5 is preferred to be changed once
in every week or about ten days in order to keep clean the writing board
device 1. Hence it is hence preferred to furnish the liquid tank 5 with a
drain valve for discharge (not shown).
The rubbing element 37 may be a roller having the sponge material formed
cylindrically about the support shaft, and it is preferred to rotate and
drive this roller in reverse direction of the moving direction by known
driving means for the purpose of enhancing a high rubbing effect. At this
time, as shown in FIG. 6, the feed pipe 34 having nozzle holes 36 may be
used as support shaft. In such a case, the liquid discharged from the
support shaft exudes through the rubbing element 37, and decreases scatter
of the liquid, thereby contributing to the compact design of the
applicator. As the rubbing element. aside from the sponge, cloth material
of high water absorption property such as felt, or a brush using nylon
bristles as shown in FIG. 7 may be also used. In such a case, the rubbing
effect is exhibited by the tip of bristles, and liquid is soaked among the
bristles. As the brush, a roller type rotary brush may be formed as
mentioned above.
The sliding frame 3 may be supported movably in the vertical direction, or
the guide rail 20 may be disposed on a plate 9, and the sliding frame may
be directly supported on the plate 9.
(EXAMPLES)
Using the following applicators (A) to (F), water (liquid) was applied on
each writing surface, and the writing surface was rubbed together with
water, and the ink decoloring state of the written mark, and the removal
state of the decolored. ink were compared, and the results are shown in
Table 2. The ink. removal state was compared by the recoloring state when
the ink coloring matter was applied. As the ink, sample 7 (black) in Table
1 was used.
The water application and rubbing means was composed as specified below:
(A) Using three knitted cords knitting cotton yarns in a tubular form, the
knitted cords are brought into contact with the writing surface while
feeding water thereon, and water is applied. (Applicator feed speed: 15
cm/sec)
(B) A rotary brush planting cotton piles is rotated at 300 rpm, and the
writing surface is rubbed. Water is supplied to the rotary brush to soak.
(Application feed speed: 15 cm/sec)
(C) Water from nozzle holes is directly discharged on the writing surface
to apply water. (Applicator feed speed: 15 cm/sec)
(D) The writing surface is rubbed with a rectangular block made of sponge
material. Water is fed to the block to soak. (Application feed speed: 40
to 50 cm/sec)
(E) The writing surface is rubbed with a rectangular block made of sponge
material. Water is fed to the block to soak. (Applicator feed speed: 15
cm/sec)
(F) Water applied on the writing surface is wiped off by rubber blade.
(Applicator feed speed: 15 cm/sec)
The decolored state and ink removal state were evaluated in four ranks 1 to
4 as follows.
1: Almost no effect
2: Slightly effective but insufficient.
3: Satisfactory but not perfect.
4: Almost perfectly erased.
TABLE 2
______________________________________
Application,
rubbing means:
A A + B B B + B C C + F
D E E + F
______________________________________
Ink decolored
4 4 4 4 4 4 4 4 4
state
Ink removal
1 2 2 3 1 3 2 3 4
state
______________________________________
As shown in Table 2, by application of water, the ink can be completely
decolored, and rubbing by the block of sponge and rotary brush is
effective for removing the ink. The rubber blade is known to contribute to
removal of ink aside from the dripping effect. Therefore, the rubber blade
functions as rubbing element, and it is more preferable to combine with
other rubbing element such as sponge material.
Incidentally, as the liquid for erasing, a mixture of water and surface
active agent, a mixture of surface active agent and solvent such as
ethylene glycol or polyethylene glycol, or a mixture of the surface active
agent and the solvent are used instead of water.
Referring then to FIGS. 8 to 13, a device 1B of a second embodiment is
described, in which the white board 2 is composed of a loop sheet 47 and a
support frame 48 supporting the sheet 47 rotatably in the lateral
direction.
As shown in the drawings, the white board 2 of the device 1B of the second
embodiment is composed of the sheet 47 and support frame 48. The sheet 47
is preferably made of, for example, a woven cloth of which face and back
sides are coated with synthetic resin such as vinyl to form a
non-expand/shrink waterproof sheet base material, being coated with
fluororesin or the like. The outer surface of the sheet 47 used as the
writing surface S is processed by mat treatment. FIG. 8 shows the device
from the rear side Re.
The support frame 48 is of portal shape coupling between the upper ends and
between the middle parts of a pair of vertical frames 49, 49 respectively
by means of horizontal upper lateral frame and middle lateral frame 51,
and a leg piece 53 is disposed at the lower end of the vertical frame 49.
The support frame 48 also comprises a driving element 55 including a pair
of support shafts 54 for supporting the sheet 47 rotatably in the lateral
direction.
The driving element 55 comprises a pair of gear boxes 56 provided on the
top of both ends of the lateral frame 50, a drive shaft 57 stretching
between the gear boxes 56, 56, and a motor M1 coupled with one gear box 56
for driving the drive shaft 57, and this motor M1 is operated by a switch
52, for example, provided in the support frame 48.
Each vertical frame 49 is nearly in a pi-section opening the mutually
confronting inward surfaces between the lateral frames 51, 51, and the
support shaft 54 having the upper and lower ends pivoted rotatably by the
support frame 48 is disposed in this pi-section. The upper end of each
support shaft 54 is gear coupled with the gear box 56 individually, and
each support shaft 54 is rotated and drive in the same direction by the
motor M1, thereby assuring the wide and long sheet 47 to rotate. Or only
one support shaft 54 may be driven, and the sheet 47 is stretched by
proper tension means (not shown), for preventing looseness in the
embodiment.
The support frame 48 is provided with a back plate 58 for the ease of
writing by supporting the writing surface S of the sheet 47 from the back
side like a desk pad, and the back plate 58 is formed in a hollow box in
the embodiment linking between the lateral frames 50, 51, and a compressed
air feeder 59 such as compressor attached to the lateral frame 51 is
provided in the hollow space. Multiple fine pores communicating with the
hollow space are pierced in the back plate 58, and when the sheet 47
rotates, compressed air is discharged from the pores, and excessive
abrasion between the sheet 47 and back plate 58 is prevented, thereby
extending the wear life of the sheet 47. Accordingly, the compressed air
feeder 59 is operated synchronously or asynchronously with the motor M1 by
the switch 52.
In the support frame 48, an opening 60 having the outward surface opened is
formed in the vertical frame 59 at the downstream side of the peripheral
direction of the white board 2 as seen from the front side Fr, and the
sheet 47 is wound around the support shaft 54 to expose the folded winding
part 47A, and the applicator 7 is provided in the opening 60.
The applicator 7 comprises a long box-shaped frame 61 attached to the
opening 20, a rubbing element 62 accommodated inside, and a feed pipe 63
for feeding liquid.
The frame 61 formed in a pi-section opened in the inward surface
confronting the opening 60, and is attached to the vertical frame 49 being
spaced from the opening 60 through a guide 64. The guide 64 comprises, in
this embodiment, plural parallel guide shafts 64A attached to the front
and rear side of the vertical frame 49 and extending parallel to the
support frame 47, and a guide pipe 64B attached to the frame 61 having
guide holes communicating with the guide shafts 64A, and the frame 61
moves parallel along the guide shafts 64A from the mutually contacting
position R1 of the rubbing element 62 and writing surface S to the
separating position R2. In the frame 61, the rubbing element 62 and
writing surface S may be joined so as to be free to space by means of
hinge or the like.
The rubbing element 62 is a rotary roller in this embodiment, and
integrally comprises a rubbing element 66 made of sponge or the like,
around a central shaft 65 having upper and lower ends pivoted on the frame
61, being parallel to the support shaft 54.
The feed pipe 63 is erected parallel to the rubbing element 62, and tiny
holes are pierced in the circumference toward the rubbing piece 66, and
the liquid tank 5 is connected to the lower end of the feed pipe 63
through the pump 5.
The rubbing element 62 is rotated and driven in reverse direction of the
peripheral direction of the sheet by known driving means (not shown), and
the rubbing element 62 soaking the liquid rubs the writing surface S in
the winding part 47A. Or, the liquid from the tiny holes in the feed pipe
63 may be injected like a shower on the writing surface S directly. The
rubbing element 62 may be, besides, fixed so as not to rotate, or rotated
and driven in the same direction as the peripheral direction, and the
rotating speed at this time is different from the peripheral speed.
The rubbing element 62 may be formed with the feed pipe as the central
shaft same as in FIG. 6.
FIG. 10 shows an example in which the rubbing element 62 is an antistatic
brush. As shown in the drawing, for example, a surface 67S curved along
the winding part 47A is formed in a base part 67 using the feed pipe 63,
and plural nozzle holes are provided in the surface 67S, and bristles 68
are planted.
Incidentally, as shown in FIG. 11, in a base part 67 using the frame 61,
plural rubbing elements 62 in block form made of sponge material may be
disposed separately, and the feed pipe 63 may be fitted among the rubbing
elements 62 to constitute like the applicator 7 in the first embodiment.
On the other hand, it is possible to insert a rubbing sheet 120 between a
element 62 and the writing surface S as shown in FIG. 20. The rubbing
sheet 120 is stocked as a winding roll, and when the rubbed part of the
sheet becomes soiled, a roll of the sheet 120 is rewound for a specific
length and the soiled part cut off.
The applicator 7 is provided with rubber blade 69 for dripping as shown in
FIG. 9. The rubber blade 69 is fixed at a downstream position of the
rubbing elements 62, and this rubber blade 69 is useful for preventing the
liquid from scattering widely, and hence it may be disposed at both
upstream side and downstream side of the rubbing elements 62 as shown in
FIG. 10.
In this embodiment, to further accelerate drying of the writing surface S,
in the support frame 48, a drier 73 for forced drying is disposed at the
downstream side of the rubber blade 69. The driver 73 is a fan heater in
the embodiment, and when the sheet 47 rotates, hot air is blown nearly
over the entire width of the dripped writing surface S. The drier 73 may
be, aside from the blower, a heater making use of radiation heat, or
without using drier 73, it may be dried in air.
The sum as in the first embodiment, as the liquid tank 5, a cartridge type
water tank 43 is provided, and a pan 40 is provided beneath the applicator
7. A feedback path 12B having a filtering device 42 is connected between
the pan 40 and liquid tank 5.
The sheet 47 is wound, in addition to the support shafts 54, 54 as shown in
FIG. 12, in a first auxiliary shaft 71A located behind one support shaft
54A, and a second auxiliary shaft 71B dislocated to the other support
shaft 54B side between the first auxiliary shaft 71A and support shaft
54A, and a recess 70 is formed between the support shaft 54 and first and
second auxiliary shafts 71A, 71B. In this recess 70, various applicators 7
are disposed so that the applicators 7 may be concealed.
FIG. 13 shows an example of white board 2 preferably used in a wide room
such as a convention hall. As shown in the drawing, the white board 2
comprises a loop base board 74 flexibly coupling plural small long pieces
74A of light weight and high rigidity made of plastic or the like, and a
sheet 47 integrally adhered to the outer circumference thereof, and the
sheet 47 is wound between support shafts 54 together with the base board
74, and supported rotatably. The distance between the support shafts 75 is
set relatively wide, and the peripheral trace 75 of the sheet 47
confronting the front side is curved in an concave arc form through a
guide 76, thereby enabling to read from a wide writing surface S. The
guide 76 is composed of a guide roller 77 arranged along the concave arc
trace, for example, in the lateral frame pieces 50, 51. In other
embodiment, using a concentric chain wheel with the support shaft 54, for
example, a drive chain Is run along the peripheral trace 75 to suspend and
support individually each base board 74 from the link piece of the drive
chain, and the sheet 47 may be adhered to the entire outer circumference
to compose the white board 2. At this time, each base board 74 is coupled
flexibly and endlessly through the sheet 47 and drive chain, and the drive
chain functions as the guide 76.
FIG. 14 to FIG. 19 relate to a device 1C in a third embodiment in which the
white board 2 is composed of the sheet 47, and a support frame 78 for
supporting the sheet 47 rotatably in the longitudinal direction. FIG. 15
shows the device from the rear side Re.
The support frame 78 is a portal shape, as shown in FIG. 14 and FIG. 15 in
the embodiment, coupling between upper ends and between middle ends of a
pair of vertical frames 79, 79, and a leg 83 is disposed at the lower end
of each vertical frame 79. The support frame 78 has a driver 85 for
rotating the sheets 47A, 47B in the longitudinal direction.
The driver 85 comprises a drive shaft 86 stretched between the upper ends
of the vertical frame 79, first, second and third guide shafts 91, 92, 93
and a tension shaft 95 provided through a side plate 87 disposed at the
inner side of the vertical frame 79.
The drive shaft 86 comprises, as schematically shown in FIG. 17 for
example, a pair of right and left outer tubes 97A, 97B externally inserted
rotatably through a bearing piece 96 on the central axis between the
vertical frames 79, 79. At the outward ends of the outer tubes 97A, 97B,
for example, gears 99 such as worm wheels are affixed, and each gear 99 is
engaged with a gear 100 such as worm disposed on each output shaft of the
motors M2, M2 mounted, for example, on a horizontal frame 80. Therefore,
the outer tubes 97A, 97B can be rotated independently of the operation of
the motors M2, and the sheets 47A, 47B wound on the outer tubes 97A, 97B
can be driven individually.
The guide shafts 91, 92, 93 are pivoted between the side plates 87, 87 as
shown in FIGS. 15, 16, and the first and second guide shafts 91, 92
receive the back side of the sheets 47A, 47B, and positioned beneath the
drive shaft 86 and are installed at the same height mutually in the
embodiment. The third guide shaft 93 receive the surface of the sheets
47A, 47B, and is disposed behind the second guide shaft 92.
The tension shaft 95 is a pair of right and left rotary shafts for
receiving the back sides of the sheets 47A, 47B, and the tension shafts
95A, 95B are installed adjustably in the height position up and down
between the side plates 87, 87 and a pair of side plate pieces 89A, 89B
parallel to each other projecting backward from the middle lateral frame
piece 81. Therefore, the tension shafts 95A, 95B are flexibly stretched
without loosening the sheets 47A, 47B.
The support frame 78 has a back plate 102 for supporting the sheets 47A,
47B on a flat surface from the back side, disposed in the region R between
the drive shaft 87 and first guide shaft 91.
The applicator 7 is a roller rubbing element 104 of a relatively large
diameter having a rubbing piece composed of sponge material disposed at
the surface side in this embodiment, and is pivoted between, for example,
the side plates 87, 87, at a position contacting with the first and second
guide shafts 91, 92. The rubbing element 104 is connected to a rotary
driver 103 in this embodiment.
The rotary driver 103 has a motor M3 mounted, for example, on a vertical
frame 79 through a mounting plate on the inner side, and a chain wheel
provided at the output shaft of the motor M3 and a chain wheel provided at
one end of the rubbing element 104 are coupled with an endless belt 103A.
Therefore, the rubbing element 104 can contact with the surface of the
sheets 47A, 47B between first and second guide shafts 91, 92, and rubs the
writing surface S. The rubbing element 104 may be divided into right and
left halves, and rotated and controlled independently in the right and
left halves same as the drive shaft 86.
The liquid tank 5 is a container with a top opening in the embodiment, and
is detachably held on the middle lateral frame 81.
The liquid tank 5 holds the liquid to a height for partly soaking the
rubbing element 104.
In the liquid tank 5, as shown in FIGS. 16, 18 in the embodiment, a roll
104 contacting with the rubbing element 104 is pivoted inside, and the
lower edge of the roll 105 is positioned near the bottom of the liquid
tank 5. Therefore, if the remainder of the stored liquid decreases, it is
guaranteed that the rubbing element 104 adsorbs water through the roll
105. As the roll 105, sponge, felt, cloth or other material of which water
absorption property is same as or larger than the rubbing element 104 is
preferred. The roll 105 can move parallel vertically, and is preferred to
be thrust upward with spring piece or the like, and hence it is easier to
take out from the front of the liquid tank 5, and moreover by installing,
the roll 105 and rubbing element 104 contact with each other.
Therefore, when the sheet 47 is wound in the vertical direction, liquid can
be supplied to the writing surface S without using pump.
In the embodiment, the support frame 78 is furnished with a drier 106 same
as the drier 73, and a refill tank 107 for refilling the liquid tank 5
with liquid. The refill tank 107 may, aside from directly supplying liquid
into the liquid tank 5, be automatically supplied through, for example,
pipe, closing valve, or the like.
Incidentally, the sheet 47 may be wound only on two support shafts, that
is, the drive shaft 86 and first guide shaft 91.
In the writing board device 1 of the invention may be further provided
with, as shown in FIG. 19, a coupler 108 comprising an engaging hook 108A
for coupling between vertical frames, for example, and a detent pin 108B
or the like, and multiple devices i may be coupled horizontally.
As the applicator 7, those disclosed in the first to third embodiments may
be properly combined and used in each device 1, so that the writing board
device 1 of the invention may be modified in various forms.
Concerning rotation of the sheet 47, aside from the lateral direction and
vertical direction mentioned above, lateral and vertical directions may be
combined as shown in FIG. 21.
A support frame 110 for rotating the sheet 47 by combining vertical and
lateral directions comprises vertical main rollers 111A, 111B disposed at
right and left ends, a vertical middle roller 112 disposed between them, a
pair of front and rear slant rollers 113A, 113B inclined sideways at a
slant angle of 45 degrees disposed between the vertical middle roller 112
and one vertical main roller 111B, and a horizontal lateral roller 114
positioned beneath the slant rollers 113A, 113B. The sheet 47 is wound in
the sequence of one vertical main roller 111A.fwdarw.other vertical main
roller 111B.fwdarw.vertical middle roller 112.fwdarw.front slant roller
113A.fwdarw.lateral roller 114.fwdarw.rear slant roller 113B
.fwdarw.vertical main roller 111A, and the vertical peripheral circuit is
composed among the slant roller 113A, lateral roller 114 and rear slant
roller 113B, while the horizontal peripheral circuit is composed among the
remainder.
At this time, it is preferred to form the liquid tank and. applicator 7 in
the vertical peripheral circuit, in particular, in the folding portion of
the lateral roller 114 at the lowest end, so that the use of pump or the
like may be omitted.
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